/* LzFind.h -- Match finder for LZ algorithms
2021-07-13 : Igor Pavlov : Public domain */

#ifndef __LZ_FIND_H
#define __LZ_FIND_H

#include "7zTypes.h"

EXTERN_C_BEGIN

typedef UInt32 CLzRef;

typedef struct _CMatchFinder
{
	Byte* buffer;
	UInt32 pos;
	UInt32 posLimit;
	UInt32 streamPos;  /* wrap over Zero is allowed (streamPos < pos). Use (UInt32)(streamPos - pos) */
	UInt32 lenLimit;

	UInt32 cyclicBufferPos;
	UInt32 cyclicBufferSize; /* it must be = (historySize + 1) */

	Byte streamEndWasReached;
	Byte btMode;
	Byte bigHash;
	Byte directInput;

	UInt32 matchMaxLen;
	CLzRef* hash;
	CLzRef* son;
	UInt32 hashMask;
	UInt32 cutValue;

	Byte* bufferBase;
	ISeqInStream* stream;

	UInt32 blockSize;
	UInt32 keepSizeBefore;
	UInt32 keepSizeAfter;

	UInt32 numHashBytes;
	size_t directInputRem;
	UInt32 historySize;
	UInt32 fixedHashSize;
	UInt32 hashSizeSum;
	SRes result;
	UInt32 crc[256];
	size_t numRefs;

	UInt64 expectedDataSize;
} CMatchFinder;

#define Inline_MatchFinder_GetPointerToCurrentPos(p) ((const Byte *)(p)->buffer)

#define Inline_MatchFinder_GetNumAvailableBytes(p) ((UInt32)((p)->streamPos - (p)->pos))

/*
#define Inline_MatchFinder_IsFinishedOK(p) \
	((p)->streamEndWasReached \
		&& (p)->streamPos == (p)->pos \
		&& (!(p)->directInput || (p)->directInputRem == 0))
*/

int MatchFinder_NeedMove(CMatchFinder* p);
/* Byte *MatchFinder_GetPointerToCurrentPos(CMatchFinder *p); */
void MatchFinder_MoveBlock(CMatchFinder* p);
void MatchFinder_ReadIfRequired(CMatchFinder* p);

void MatchFinder_Construct(CMatchFinder* p);

/* Conditions:
	 historySize <= 3 GB
	 keepAddBufferBefore + matchMaxLen + keepAddBufferAfter < 511MB
*/
int MatchFinder_Create(CMatchFinder* p, UInt32 historySize,
	UInt32 keepAddBufferBefore, UInt32 matchMaxLen, UInt32 keepAddBufferAfter,
	ISzAllocPtr alloc);
void MatchFinder_Free(CMatchFinder* p, ISzAllocPtr alloc);
void MatchFinder_Normalize3(UInt32 subValue, CLzRef* items, size_t numItems);
// void MatchFinder_ReduceOffsets(CMatchFinder *p, UInt32 subValue);

/*
#define Inline_MatchFinder_InitPos(p, val) \
	(p)->pos = (val); \
	(p)->streamPos = (val);
*/

#define Inline_MatchFinder_ReduceOffsets(p, subValue) \
    (p)->pos -= (subValue); \
    (p)->streamPos -= (subValue);


UInt32* GetMatchesSpec1(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte* buffer, CLzRef* son,
	size_t _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 _cutValue,
	UInt32* distances, UInt32 maxLen);

/*
Conditions:
  Mf_GetNumAvailableBytes_Func must be called before each Mf_GetMatchLen_Func.
  Mf_GetPointerToCurrentPos_Func's result must be used only before any other function
*/

typedef void (*Mf_Init_Func)(void* object);
typedef UInt32(*Mf_GetNumAvailableBytes_Func)(void* object);
typedef const Byte* (*Mf_GetPointerToCurrentPos_Func)(void* object);
typedef UInt32* (*Mf_GetMatches_Func)(void* object, UInt32* distances);
typedef void (*Mf_Skip_Func)(void* object, UInt32);

typedef struct _IMatchFinder
{
	Mf_Init_Func Init;
	Mf_GetNumAvailableBytes_Func GetNumAvailableBytes;
	Mf_GetPointerToCurrentPos_Func GetPointerToCurrentPos;
	Mf_GetMatches_Func GetMatches;
	Mf_Skip_Func Skip;
} IMatchFinder2;

void MatchFinder_CreateVTable(CMatchFinder* p, IMatchFinder2* vTable);

void MatchFinder_Init_LowHash(CMatchFinder* p);
void MatchFinder_Init_HighHash(CMatchFinder* p);
void MatchFinder_Init_4(CMatchFinder* p);
void MatchFinder_Init(CMatchFinder* p);

UInt32* Bt3Zip_MatchFinder_GetMatches(CMatchFinder* p, UInt32* distances);
UInt32* Hc3Zip_MatchFinder_GetMatches(CMatchFinder* p, UInt32* distances);

void Bt3Zip_MatchFinder_Skip(CMatchFinder* p, UInt32 num);
void Hc3Zip_MatchFinder_Skip(CMatchFinder* p, UInt32 num);

void LzFindPrepare(void);

EXTERN_C_END

#endif
